Drill holder



Jan. 202 193.1.` f A.1. v. osTLUND 1,789,830

. y DRILL HOLDER Filed spt. 28. 1927 Patented Jan. 20, 1931 iasasao- A UNITED STATES PATENT OFFICE This invention relates to a drill holding and driving means and is best adapted for use on machines wherein the drill drivingl spindle and drill are withdrawn from the piece worked upon by positive power.

One of the obiects of my invention is to provide a driving' means that will shear otr when subject to twisting,l strains greater than the drill being' driven can stand.

Further objects are to provide a resilient means for withdrawing` the drill from the finished hole and to provide holding means associated with said resilientwithdrawing means, so built as to shear olf if the drill sticks in the hole and offers too great a resistance to being withdrawn.

It is also desirable to provide a means for automatically centering the drill driving` col; let when the drill point has entered a guide bushing. These and further objects will be better explained in the specification taken in connection with the drawings wherein:

Fig. l is aside view, partly inseetion, of -a drill, a drill holder and a driving;` spindle embodyingmy invention.

Fig. 2 is a view taken on line 2-2 of Fig. l.

Fig. 3 is a sectional view taken on line 3-3 of Fig. l.

Referring` to t lThe shaft 10 has a. hole l2 thru it and the enlrance to Athe hole l2 is chanifered as at lll. A drill holding;- collet 'lG rides within the hole l 2 and is centered therein by a curved shoulder 1.8 `which centers on the chainfer lil. A drill 2O is held in the collet 16 by-a pin which extends into slots 24 of a spindle l and serves as a drivin means between the spindle l0 and drill 20. ,1 n

Screwed into the end of the spindle are. two studs 26 and 27. Slidably mounted on the studs 26 and 27 is a circular collar 28 which is forced against the drill collet 16 by a spring 30 on each stud. A. Cotter pin 32 he drawings, there is shown' a driving spindle l() which may be attached to the turret of an automatic lathe, a drill press spindle or the spindle of any machine with which it is desirable to feed a tool into and out of a piece of work being operated JOI-IN V. OSTLUND, OF NEVCASTL, INDIANA DRILL HGLDER Application filed September 28i 1927. Serial No. 222,498.

the drill 20.

mal position.

preferred form of my 1 appended claims.

lVhat l claim is:

ing a hollow spindle, a

loosely fitting the openi resilient means secured to the end of said spindle and adapted to urge said sleeve into said hollow spindle and a pin passing thru said spindle, sleeve and tool to hold the tool in the sleeve and to act as a driving,r means between the spindle and the sleeve and tool.

2. A device of the class described comprising, a hollow spindle, a tool holdin()- sleeve loosely fitting the opening` in said spindle,

a tool in said sleeve, a curved shoulder on said sleeve adaptedto enga-ge the outergdge of said spindle,studs inthe end of said spin- VV and washer 34E are secured on each stud to act as spring` retainers. In operation the drill 2O is driven by the spindle 10 thru the pin The springs 30,' in cooperation with the plate 28, tend to keep the drill and collet acurately centered 4in the spindle l() by forming the shoulder 'i8 against the chamfer 14 inA the spindle l0. T he driving,` pin 22 is made of a material of low shearing strength so that if the drill should bind the pin will shear olf and no harm will be done to the drill. The diameter and. shearing,` strength of the `pin 22 will depend upon Vthe size and strengthv of ln machining` the chamfer 14 on the shaft 65 l0, a boring tool, not shown, is placed in a chuck and the chamfer cut radially on the center line of the chuck. feet alignment of the collet 16 regardless of the center line thru the shaft. y

Assuming the drill 2O to be stuck in Jthe work and the pin 22 to have sheared off. The l s yindle l0 will be moved to the right thereby con'ipressing the springs 30 until the collar 28 causes the cotter pins 3 allowing the spindle 10 to return to its nor- This assures per Q t0 Shear olf thus 75 c While I have shown what I deem to be the nvention it 1s to be understood that various changes may be made without departing from the spirit of myinvention and that it is not my` intention to limit its scope other than by the terms of the il. A. device of the class described. compris tool holding sleeve ng in said spindle,

elle, a plate surrounding said tool and abutting against said sleeve, springs on said studs foiforcing said plate againstsaid sleeve to urge said sleeve againsJ said spindle7 a pin 5 thru said sleeve and tool to Secure said tool Within Said sleeve, said spindle having slots in the Wall thereof of said spindle thru which Said pin projects and foil-111s a cliivingineans between said :spindle and sleeve, said slots allowing free axial movement of the Jcool7 sleeve and pin in respeot'to thenspindle,

JOHN V. OSTLUND. 

